London: Swimmers Michael Phelps and Ryan Lochte will slug it out for one last time on Thursday while Britain's Olympic cyclists seek to draw inspiration from Bradley Wiggins's storming victory in the individual time trial.

The two Americans teamed up on Tuesday in the squad that crushed the rest of the field in the 4x200 metres freestyle relay to give Phelps his 19th Olympic medal, an all-time record.

The duo now go head to head in the 200 individual medley - a final tantalising clash before Phelps retires.

Lochte drew first blood in London by winning the 400 version on Saturday, pushing Phelps into fourth place.

Phelps is bidding again for the elusive feat of becoming the first male swimmer to win the same event at three successive Olympics.

"We love racing against each other," he said. "Neither one of us likes to lose. I like to say we bring out the best in one another."

Olympic track cycling action gets underway with Britain's Victoria Pendleton, a nine-times world champion, renewing her battle with Australia's Anna Meares and hoping to end her career on a high on home soil.

With Germany holding the world titles in both team sprints, the hosts will be hard pressed to repeat their showing in Beijing where they won seven of 10 possible golds.

But they will draw inspiration from the ginger-whiskered Wiggins who followed victory in last month's Tour de France by running away with the time trial, 42 seconds ahead of Germany's Tony Martin.

China lead the medals table with 17 golds after five days of competition, ahead of the United States on 12 and South Korea on six, at a Games already packed with incident and touched by scandal.

Eight women badminton players - two top-seeded Chinese, two Indonesians and four from South Korea - were disqualified for deliberately trying to lose their matches on Tuesday night in order to get an easier draw in the knockout phase of the tournament.

The spectacle of players deliberately hitting shuttlecocks out of court and dumping serves into the net drew jeers from the fans at Wembley Arena.

"I'm very, very sorry this has happened for both the players and for the sport," Badminton World Federation secretary general Thomas Lund said.

Organisers will be hoping the focus stays firmly on the sporting action on Thursday.

In the last day of slalom competition, Slovakian twins Pavol and Peter Hochschorner will try to win a fourth consecutive Olympic gold medal in canoe double.

The all-around women's gymnastics final sees Americans Aly Raisman and Gabby Douglas vying with Russia's Victoria Komova, a day after Japan's Kohei Uchimura won the men's title and atoned for letting it slip through his fingers in Beijing.

In other late action on Wednesday, Nathan Adrian of the United States edged out Australia's James Magnussen by the smallest possible margin, 0.01 seconds, to win the 100 freestyle and the unofficial title of world's fastest swimmer.

The U.S. women won the 4x200 freestyle relay while Hungary's Daniel Gyurta broke the world record in winning the 200 breaststroke and China's Jiao Liuyang grabbed gold in the women's 200 butterfly.